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## Re: [Amps] MOSFET amp for 80 m

 To: Angel Vilaseca Re: [Amps] MOSFET amp for 80 m Roger Graves Wed, 18 Jul 2018 13:09:37 -0700
 Angel, Manfred may reply for himself, but from one of his webpages https://ludens.cl/Electron/mosfetamps/amps.html his analysis of the circuit shows that the peak voltage on the primary is 25V, which gives 6.3W on 48 Ohms. This is because when one mosfet goes to saturation, the voltage on the non-conducting mosfet goes to almost twice the supply voltage, Vcc + (Vcc-Vsat), so the total peak primary voltage is 2 X (Vcc-Vsat). Someone will surely correct me if I got this wrong. 73, Roger > On Jul 17, 2018, at 7:29 AM, Angel Vilaseca wrote: > > Hello everyone, > > On this page, > > http://lpistor.chez-alice.fr/pairf510.htm > > I found a MOSFET amp description that does not need an output transformer. > The author says that the output impedance of the transistors is 48 Ohms and > that a balun is enough. > How can this amplifier have such a high output impedance? > > And most importantly, if the output impedance is 48 Ohms and the supply > voltage is 13.8V, then how can the output power be 5-6 W? > If the formula V ** 2 / R is used, that is 13.8 * 13.8 / 48, the output power > should be less than 4 W. > > Best regards > > Angel Vilaseca HB9SLV > _______________________________________________ > Amps mailing list > Amps@contesting.com > http://lists.contesting.com/mailman/listinfo/amps _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
 Current Thread [Amps] parasitic suppressor for six meters, Jim Garland Re: [Amps] parasitic suppressor for six meters, Bill Turner Re: [Amps] parasitic suppressor for six meters, Ron Youvan [Amps] parasitic suppressor for six meters, Jim Thomson [Amps] MOSFET amp for 80 m, Angel Vilaseca Re: [Amps] MOSFET amp for 80 m, Roger Graves <= Re: [Amps] MOSFET amp for 80 m, Bill Turner